Quantification of cancer risk in glomerulonephritis

Nephrotic syndrome as a possible indicator of colonic cancer: A case report

The concept of paraneoplastic syndromes encompasses a spectrum of indirect clinical manifestations caused by secretion of bioactive products by malignant cells. Paraneoplastic glomerulopathy represent a distinct clinical entity where nephrotic syndrome can arise as a manifestation of underlying malignancies, particularly solid tumors. Membranous nephropathy is notably associated with such malignancies, highlighting the intricate relationship between nephrotic syndrome and cancer. The present study reports the case of a 44-year-old Caucasian male, smoker (22 pack-years) and chronic ethanol consumer who presented in the Emergency County Hospital of Craiova in March 2018 with abdominal distension, genital and leg edema and no prior medical history. Laboratory tests revealed inflammatory syndrome (erythrocyte sedimentation rate=110 mm/h, fibrinogen, 150 mg/dl, high levels of C reactive protein=6.87 mg/dl), as well as hypoproteinemia (total protein levels=3.90 g/l), hypertriglyceridemia=213 mg/dl, hypercholesterolemia=475 mg/dl, total urinary protein excretion of 12,500 mg/24 h and normal levels of urea (38 mg/dl) and creatinine (0.90 mg/dl). After meeting the diagnostic criteria for nephrotic syndrome (edema, proteinuria, hypoalbuminemia, and hyperlipidemia, it was investigated whether the syndrome was primary or secondary in origin. Notably, an unexplained inflammatory syndrome in conjunction with elevated tumor marker levels (carbohydrate antigen 19-9, 82.47 U/ml; Carcinoembryonic antigen-CEA=9.46 ng/ml) prompted a thorough imagistic investigation, using computer tomography. A polyp was discovered during colonoscopy, prompting a biopsy. The presence of adenocarcinoma was confirmed by histopathological analysis. The only clinical manifestation of the colonic malignancy was the symptomatic presentation of nephrotic syndrome, which led to early detection of the underlying cancer. Paraneoplastic nephropathy connects kidney disease with systemic cancer, showing that renal symptoms may aid in diagnosing hidden malignancies. Nephrotic syndrome, especially membranous nephropathy, is associated with various solid tumors. The present case demonstrated that paraneoplastic syndrome, though rare, may lead to early cancer detection. Ongoing research is essential for improving understanding, targeted therapy and patient management.

The validity of pathology codes for biopsy-confirmed kidney disease in the Danish National Patobank

Background

This study validates the application of Systematized Nomenclature of Medicine second edition (SNOMED II) codes used to describe medical kidney biopsies in Denmark in encoded form, aiming to support robust epidemiological research on the causes, treatments and prognosis of kidney diseases.

Methods

Kidney biopsy reports from 1 January 1998 to 31 December 2018 were randomly extracted from the Danish National Patobank, using SNOMED codes. A 5% sample was selected, and nephrologists assessed the corresponding medical records, assigning each case the applied clinical diagnoses. Sensitivity, specificity, positive predictive values (PPV), negative predictive values and Cohen's kappa coefficient for the retrieved SNOMED codes were calculated.

Results

A total of 613 kidney biopsies were included. The primary clinical disease groups were glomerular disease (n = 368), tubulointerstitial disease (n = 67), renal vascular disease (n = 51), diabetic nephropathy (n = 51) and various renal disorders (n = 40). Several SNOMED codes were used to describe each clinical disease group and PPV for the combined SNOMED codes were high for glomerular disease (94%), diabetic nephropathy (85%) and systemic diseases affecting the kidney (96%). Conversely, tubulointerstitial disease (62%), renal vascular disease (60%) and other renal disorders (17%) showed lower PPV.

Conclusions

SNOMED codes have a high PPV for glomerular diseases, diabetic nephropathy and systemic diseases affecting the kidney, in which they could be applied for future epidemiological research.

Causal Relationship Between Kidney Function and Cancer Risk: A Mendelian Randomization Study

RATIONALE & OBJECTIVE

Patients treated with kidney replacement therapy experience a 1.5- to 2-fold increased risk of cancer and cancer mortality compared with the general population. Whether this excess risk extends to people with earlier stage chronic kidney disease and whether reduced kidney function is causally related to cancer is unclear.

STUDY DESIGN

Two-sample Mendelian randomization (MR).

SETTING & PARTICIPANTS

Genome-wide association study (GWAS) summary statistics for estimated glomerular filtration rate (eGFR) (n=567,460) and urinary albumin-creatine ratio (UACR) (n=127,865) from the CKDGen consortium and cancer outcomes from the UK Biobank (n = 407,329).

EXPOSURE

eGFR and UACR.

OUTCOME

Overall cancer incidence, cancer-related mortality and site-specific colorectal, lung, and urinary tract cancer incidence.

ANALYTICAL APPROACH

Univariable and multivariable MR conducted for all outcomes.

RESULTS

The mean eGFR and median UACR were 91.4mL/min/1.73m2 and 9.32mg/g, respectively, in the CKDGen, and 90.4mL/min/1.73m2 and 9.29mg/g, respectively, in the UK Biobank. There were 98,093 cases of cancer, 15,850 cases of cancer-related death, 6,664 colorectal, 3584 lung, and 3,271 urinary tract cancer cases, respectively. The genetic instruments for eGFR and UACR comprised 34 and 38 variants, respectively. Genetically predicted kidney function (eGFR and UACR) was not associated with overall cancer risk or cancer death. The association between genetically predicted eGFR and UACR and overall cancer incidence had an odds ratio of 0.88 ([95% CI, 0.40-1.97], P=0.8) and 0.90 ([95% CI, 0.78-1.04], P=0.2) respectively, using the inverse-variance weighted method. An adjusted generalized additive model for eGFR and cancer demonstrated evidence of nonlinearity. However, there was no evidence of a causal association between eGFR and cancer in a stratified MR.

LIMITATIONS

To avoid overlapping samples a smaller GWAS for UACR was used, which reduced the strength of the instrument and may introduce population stratification.

CONCLUSIONS

Our study did not show a causal association between kidney function, overall cancer incidence, and cancer-related death.

PLAIN-LANGUAGE SUMMARY

Does reduced kidney function cause cancer? Patients with chronic kidney disease have been shown to have an increased risk of cancer and cancer-related death. However, it is not clear whether kidney disease is causally related to cancer or the association is due to other factors such as immune suppression and inflammation or a result of distortion of the analyses from unidentified variables (confounding). We used large, published genetic studies as well a database including 407,329 people in the United Kingdom in a series of Mendelian randomization analysis. Mendelian randomization uses the random assignment of genetic variants at birth to investigate causal relationships without confounding from measured and unmeasured confounders. We found that there is no evidence of a causal relationship between reduced kidney function and cancer.

Are patients with primary glomerular disease at increased risk of malignancy?

Over the past decade, several observational studies and case series have provided evidence suggesting a connection between glomerular diseases and the development of malignancies, with an estimated risk ranging from 5 to 11%. These malignancies include solid organ tumours as well as haematologic malignancies such as lymphoma and leukaemia. However, these risk estimates are subject to several sources of bias, including unmeasured confounding from inadequate exploration of risk factors, inclusion of glomerular disease cases that were potentially secondary to an underlying malignancy, misclassification of glomerular disease type and ascertainment bias arising from an increased likelihood of physician encounters compared with the general population. Consequently, population-based studies that accurately evaluate the cancer risk in glomerular disease populations are lacking. While it is speculated that long-term use of immunosuppressive medications and glomerular disease activity measured by proteinuria and estimated glomerular filtration rate may be associated with cancer risk in patients with glomerular disease, the independent role of these risk factors remains largely unknown. The presence of these knowledge gaps could lead to a lack of awareness of cancer as a potential chronic complication of glomerular disease, underutilization of routine screening practices in clinical care that allow early diagnosis and treatment of malignancies and underrecognition of modifiable risk factors to decrease the risk of de novo malignancies over time. This review summarizes the current evidence on the risk of cancer in patients with glomerular diseases, explores the limitations of prior studies and discusses methodological challenges and potential solutions for obtaining accurate estimates of cancer risk and identifying modifiable risk factors unique to GN populations.

Comparison of skin cancer risk between renal transplant recipients and patients with glomerular diseases in rural Queensland

INTROUDCTION

There is increased risk of skin cancer in patients with gloermular disease or those with renal transplant.

OBJECTIVES

To compare the risk of skin cancer between kidney recipients (KTRs) and patients with glomerular disease (GD).

DESIGN

The cohort comprised patients with KTRs (n = 61) and GD (n = 51) in Central and Central West Queensland, Australia. A quantitative cohort study was undertaken to study the risk of skin cancer in rural communities between two subgroups of patients with kidney diseases in relationship to immunosuppression. Statistical analyses of the differences in incidence of skin cancers between the two groups were done by chi-square test, Fisher's exact test, independent t-test and McNemar's test.

FINDINGS

KTRs with non-melanoma skin carcinoma (NMSC) increased significantly after treatment with immunosuppressants (pre-transplantation, n = 11 [18.0%], post-transplantation, n = 28 [45.9%]; p < 0.001). There were no differences in number of patients with NMSC observed in the GD group (pre-diagnosis, n = 6 [11.8%], post-diagnosis, n = 7 [13.7%]; p = 1.000). Compared to the risks at 1 year post-immunosuppressants, the incidence of NMSC of KTRs increased significantly at 3 years (20.3% vs. 35.4%, p < 0.001) and 5 years (20.3% vs. 62.2%, p < 0.001) post-immunosuppressants, whereas the increased incidence of NMSC was observed only at 5 years (2.1% vs. 11.8%, p = 0.012) in the GD cohort. The mean cumulative number of NMSC in KTRs increased significantly at 3 years (p = 0.011), and 5 years (p = 0.001) post-immunosuppressants, compared to the risks at 1 year post-immunosuppressants, however, no differences were noted in the GD cohort.

DISCUSSION

Immunosuppressants increased the risk of NMSC in KTRs. The increased risk is likely dependent on the intensity and duration of immunosuppressants.

CONCLUSION

In patients with a high risk of NMSC, reducing skin cancer risk should be considered in conjunction with the optimisation of treatment.

Subtypes of Venous Thromboembolism in Inflammatory Bowel Disease: A Nationwide Assessment

Background

Data detailing the risk of Venous Thromboembolism (VTE) subtypes among individuals with Inflammatory bowel disease (IBD) remain limited.Aims: We looked to assess the odds of VTE subtypes among hospitalized individuals with IBD as compared to those without IBD.

Materials & Methods

Using the Nationwide Inpatient Sample database, we applied a multivariable regression analysis to compare the odds of primary VTE-related hospitalizations among individuals with and without IBD from 2016 to 2020, including deep venous thrombosis (DVT), pulmonary embolism (PE), portal vein thrombosis (PVT), Budd Chiari syndrome (BCS), renal vein thrombosis (RVT), and cerebral venous sinus thrombosis (CVST).

Results

Overall, there were 15,565 primary VTE-related hospitalizations among individuals with IBD, as compared to 1,449,164 among individuals without IBD. Having IBD increased the odds for DVT (aOR = 1.34, 95%CI: 1.25-1.43), PVT (aOR = 3.16, 95%CI: 2.65-3.76), and CVST (aOR=1.45, 95%CI: 1.05-2.00), without significant increase in the odds of a PE, BCS, or RVT. Further, individuals with ulcerative colitis (UC) were at a higher risk for the majority of VTE-subtypes as compared to those with Crohn's disease (CD). Among individuals with a VTE-related hospitalization, the presence of IBD was not associated with increased mortality (aOR = 0.77, 95%CI: 0.40-1.50), but was associated with an increased length of stay (CD - 4.8 days, UC - 5.3 days, without IBD - 4.3 days, p<0.01).

Conclusions

Clinicians should retain a high index of suspicion when evaluating VTE-related symptoms among individuals with IBD, as the presence of IBD confers a higher risk of DVT, PVT and CVST related-hospitalizations, and longer stays as compared to individuals without IBD.

Increased Cancer Risk in Patients with Kidney Disease and Venous Thromboembolism: A Population-Based Cohort Study

BACKGROUND

 Venous thromboembolism (VTE) may be a harbinger of cancer in the general population. Patients with kidney disease have an a priori increased VTE risk. However, it remains unknown how a VTE affects subsequent cancer risk in these patients.

OBJECTIVES

 To examine the cancer risk in patients with kidney disease following a VTE.

METHODS

 We conducted a nationwide population-based cohort study in Denmark (1996-2017), including all VTE patients with a diagnosis of kidney disease. We calculated absolute risks of cancer (accounting for competing risk of death) and age-, sex-, and calendar-period standardized incidence ratios (SIRs) comparing the observed cancer incidence with national cancer incidence rates and cancer incidence rates of VTE patients without kidney disease.

RESULTS

 We followed 3,362 VTE patients with kidney disease (45.9% females) for a median follow-up time of 2.4 years (interquartile range: 0.6-5.4). During follow-up, 464 patients were diagnosed with cancer, of whom 169 (36.4%) were diagnosed within the first year. The 1-year absolute risk of any cancer was 5.0% (95% confidence interval [CI]: 4.3-5.8), with a SIR of 2.9 (95% CI: 2.5-3.4) when compared with the general population, and 2.0 (95% CI: 1.8-2.4) when compared with VTE patients without kidney disease. During subsequent years of follow-up, the SIRs declined to 1.5 (95% CI: 1.3-1.6) when compared with the general population, and 1.1 (95% CI: 0.9-1.2) compared with VTE patients without kidney disease.

CONCLUSION

 Patients with hospital-diagnosed kidney disease have increased cancer risk after VTE, especially within the first year following the VTE diagnosis.

Clinical covariates influencing clinical outcomes in primary membranous nephropathy

BACKGROUND

Primary membranous nephropathy (PMN) frequently causes nephrotic syndrome and declining kidney function. Disease progression is likely modulated by patient-specific and therapy-associated factors awaiting characterization. These cofactors may facilitate identification of risk groups and could result in more individualized therapy recommendations.

METHODS

In this single-center retrospective observational study, we analyze the effect of patient-specific and therapy-associated covariates on proteinuria, hypoalbuminemia, and estimated glomerular filtration rate (eGFR) in 74 patients diagnosed with antibody positive PMN and nephrotic-range proteinuria (urine-protein-creatinine-ratio [UPCR] ≥ 3.5 g/g), treated at the University of Freiburg Medical Center between January 2000 - November 2022. The primary endpoint was defined as time to proteinuria / serum-albumin response (UPCR ≤ 0.5 g/g or serum-albumin ≥ 3.5 g/dl), the secondary endpoint as time to permanent eGFR decline (≥ 40% relative to baseline).

RESULTS

The primary endpoint was reached after 167 days. The secondary endpoint was reached after 2413 days. Multivariate time-to-event analyses showed significantly faster proteinuria / serum-albumin response for higher serum-albumin levels (HR 2.7 [95% CI: 1.5 - 4.8]) and cyclophosphamide treatment (HR 3.6 [95% CI: 1.3 - 10.3]). eGFR decline was significantly faster in subjects with old age at baseline (HR 1.04 [95% CI: 1 - 1.1]).

CONCLUSION

High serum-albumin levels, and treatment with cyclophosphamide are associated with faster proteinuria reduction and/or serum-albumin normalization. Old age constitutes a risk factor for eGFR decline in subjects with PMN.

Dual-Signal Triple-Mode Optical Sensing Platform for Assisting in the Diagnosis of Kidney Disorders

As known biomarkers of kidney diseases, N-acetyl-β-d-glucosaminidase (NAG) and β-galactosidase (β-GAL) are of great importance for the diagnosis and treatment of diseases. The feasibility of using multiplex sensing methods to simultaneously report the outcome of the two enzymes in the same sample is even more alluring. Herein, we establish a simple sensing platform for the concurrent detection of NAG and β-GAL using silicon nanoparticles (SiNPs) as a fluorescent indicator synthesized by a one-pot hydrothermal route. p-Nitrophenol (PNP), as a common enzymatic hydrolysis product of the two enzymes, led to the attenuation of fluorometric signal caused by the inner filter effect on SiNPs, the enhancement of colorimetric signal due to the increase of intensity of the characteristic absorption peak at around 400 nm with increasing reaction time, and the changes of RGB values of images obtained through a color recognition application on a smartphone. The fluorometric/colorimetric approach combined with the smartphone-assisted RGB mode was able to detect NAG and β-GAL with good linear response. Applying this optical sensing platform to clinical urine samples, we found that the two indicators in healthy individuals and patients (glomerulonephritis) with kidney diseases were significantly different. By expanding to other renal lesion-related specimens, this tool may show great potentials in clinical diagnosis and visual inspection.

Role of synthetical amynoquinone ethyl 2-(1,4-dioxo-1,4-dihydronaphthalen-2-ylamino) acetate in inhibition of Ehrlich's tumor

Quinones are naturally or synthetically occurring secondary metabolites that have various bio-dynamics, highlighting their antitumor potential. This has been explored through their selective cytotoxicity, and studies in medicinal chemistry about the relation between biological activity versus chemical structure may lead to the solution of the toxicity problems associated with quinones. In this context, the antitumor effect of a synthetic naphthoquinone, named Ethyl 2-(1,4-Dioxo-1,4-Dihydronaphthalen-2-Ylamino) Acetate, was tested using mice transplanted with Ehrlich ascitic tumor as an experimental model. The acute toxicity test was performed using 30 mice that received the aminoquinone at doses of 100, 200, 300, and 600 mg/kg. After evaluation of the clinical findings in the spontaneous activity tests, the LD50 calculation for the test substance showed low levels of toxicity at doses lower than 244.11 ± 23.29 mg/kg. Thus, three experimental groups were established, where animals transplanted with tumor cells received NaCl vehicle solution (control, n = 6), and the others were treated with 71.7 mg/kg of Methotrexate (n = 6) or 20 mg/kg of Aminoquinone (n = 6). All administrations were intraperitoneal, in a single dose. Three days after the implantation of the tumor cells the animals were weighed daily and evaluated for tumor biometry and development. The treatments occurred five days after the implantation of the tumor cells and were extended for 7 more days. At the end of the 12-day experimental period, all animals were euthanized for biochemical and histopathological analyses of the tumors and vital organs. The spontaneous activity test showed that the amount of responses associated with the nervous system tends to increase with the increase in dosage, highlighting the excitatory effect on the central nervous system in almost all dosages employed, followed by depressant activities on this system. There was a significant tumor reduction, both in animals treated with methotrexate (71.7 %) and in those treated with aminoquinone (91.6 %) in the control group. There was no significant difference in tumor volume between the animals treated with aminoquinone or methotrexate. The histopathological analysis revealed that in both treatments there were fewer mitoses in the tumor mass compared to the control group. However, there was apparent toxicity to the liver, heart, and left kidney in the treatment with methotrexate compared to aminoquinone. The significant capacity for tumor reduction presented by aminoquinone allows pointing it as a promising alternative for the development of a more efficient drug to control tumor development, being necessary for the development of new studies to deepen the knowledge about its mechanisms of action.

An integrated skin cancer education program in renal transplant recipients and patients with glomerular disease

Sun-protective strategies focusing on skin cancer awareness are needed in immunosuppressed patients at risk of skin cancers. The study aims to determine the effect of an integrated skin cancer education program on skin cancer awareness and sun-protective behaviours in renal transplant recipients (RTRs) and patients with glomerular disease (GD) treated with long-term immunosuppressants. A pilot prospective cohort study in Central Queensland, Australia was undertaken among adult RTRs and patients with GD, who completed survey questionaries on skin cancer and sun-health knowledge (SCSK), sun-protection practices and skin examination pre- and post-education. Fifty patients (25 RTRs, 25 patients with GD) participated in the study. All of them completed questionnaires at pre-, 3-month post-education and 92%(n = 46) at 6-month post-education. There was a significant increase in SCSK scores from baseline at 3-months (p < 0.001) and 6-months post-intervention (p < 0.01). Improved knowledge was retained for 6 months after education. There were changes in 2 of 8 photoprotective behaviours at 6 months. Interventional education enhanced regular self-skin examination rate (p < 0.001) as well as the frequency of full skin checks by general practitioners (GPs) (p < 0.001). Overall, RTRs had better compliance with sun-protective methods and higher skin examination rates by themselves and/ or GPs before and after the intervention of education compared to patients with GD. To conclude, an integrated skin cancer education program improved knowledge of skin cancer and skin health as well as the frequency of self-skin examination and formal skin assessments. However, improvement in patient compliance did not extend to other sun-protective practices.

Critical evaluation of cancer risks in glomerular disease

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The increased cancer incidence in patients with glomerular disease can be secondary to an intrinsic immune dysfunction associated with the disease or/and extrinsic factors, especially immunosuppressants.

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Paraneoplastic glomerulopathy is sometimes misdiagnosed as primary glomerulopathy.

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The treatment for paraneoplastic glomerulopathy is different from primary glomerular disease.

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In membranous nephropathy, serum circulating autoantibodies against PLA2R and THSD7A, immunohistochemical tissue markers for glomerular PLA2R, THSD7A and specific types of immunoglobulin G (IgG) may be used for identifying underlying malignancies.

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A scheme of screening of cancers frequently reported in the setting of glomerular disease is important.

The increased cancer incidence in patients with glomerular disease can be secondary to an intrinsic immune dysfunction associated with the disease or/and extrinsic factors, especially immunosuppressants. The treatment for paraneoplastic glomerulopathy is different from primary glomerular disease. Immunosuppressive therapy often used for primary glomerulopathy may aggravate concomitant cancers in patients with paraneoplastic glomerulopathy. In membranous nephropathy (MN), measurement of serum circulating autoantibodies against podocyte transmembrane glycoprotein M-type phospholipase A2 receptor (PLA2R) and thrombospondin type 1 domain-containing 7A (THSD7A), immunohistochemical staining of kidney tissue for glomerular PLA2R, THSD7A, neural epidermal growth factor-like 1 protein (NELL-1) and specific types of immunoglobulin G (IgG) may be useful adjuncts when screening for underlying malignancies. This review addresses overall cancer risks in individuals with glomerular diseases and employment of biomarkers available for MN. We propose a scheme of screening of cancers frequently reported in the setting of glomerular disease.

A Focus Group Study of Self-Management in Patients With Glomerular Disease

INTRODUCTION

Patients with glomerular disease experience symptoms that impair their physical and mental health while managing their treatments, diet, appointments and monitoring general and specific indicators of health and their illness. We sought to describe the perspectives of patients and their care partners on self-management in glomerular disease.

METHODS

We conducted 16 focus groups involving adult patients with glomerular disease (n = 101) and their care partners (n = 34) in Australia, Hong Kong, the United Kingdom, and United States. Transcripts were analyzed thematically.

RESULTS

We identified the following 4 themes: empowered in autonomy (gaining confidence through understanding, taking ownership of disease and treatment, learning a positive health approach); overwhelmed by compounding treatment burdens (financially undermined and depleted, demoralized by side effects and harms, frustrated by fragmented and inflexible care, fear of possible drug harms); striving for stability and normalcy (making personal sacrifices, maximizing life participation, attentiveness to bodily signs, avoiding precarious health states, integrating medicines into routines); and necessity of health-sustaining relationships (buoyed by social support, fulfilling meaningful responsibilities, sharing and normalizing experiences, seeking a trusting and respectful alliance).

CONCLUSION

Patients with glomerular disease and their care partners value their capacity for autonomy and disease ownership, stability of their health, and relationships that support self-management. Strategies directed at strengthening these factors may increase self-efficacy and improve the care and outcomes for patients with glomerular disease.

Cancer risk in patients with IgA nephropathy: a Swedish population-based cohort study

BACKGROUND

IgA nephropathy (IgAN) is the most common primary glomerulonephritis affecting all ages and both sexes, but there is a lack of studies on its association with cancer and whether it is a paramalignant condition.

METHODS

In a Swedish population-based cohort study we compared the risk of cancer among 3,882 biopsy-verified IgAN patients diagnosed during 1974-2011 with 19,341 reference individuals and followed them until 2015. Cox regression was used to estimate hazard ratios (HRs) for cancer in IgAN patients versus controls, and conditional logistic regression assessed the risk of cancer before the IgAN was confirmed.

RESULTS

During a median follow-up of 12.6 years, 488 (12.6%) patients with IgAN and 1,783 (9.2%) matched reference individuals were diagnosed with cancer (HR 1.70; 95% confidence interval, 95%CI, 1.52-1.89). The increased risk was only seen in IgAN patients developing end stage renal disease (ESRD), with an HR of 4.01 (95%CI 3.33-4.82) for any cancer and HR of 2.22 (95%CI 1.79-2.75) when excluding non-melanoma skin cancer (NMSC). Non-ESRD IgAN patients did not have an increased overall cancer risk (HR 1.13; 95%CI 0.99-1.30). There was no increased risk of cancer preceding IgAN diagnosis (odds ratio 1.10; 95%CI 0.92-1.32).

CONCLUSION

We found no support for IgAN being a paramalignant condition. There was an increased risk of cancer in IgAN patients, but only for those with ESRD. Our results indicate approximately 6 extra cancer case per 100 IgAN patients with ESRD per 10 years, or >17 extra cases if including NMSC as well.

Coding practice in national and regional kidney biopsy registries

Background

Kidney biopsy registries all over the world benefit research, teaching and health policy. Comparison, aggregation and exchange of data is however greatly dependent on how registration and coding of kidney biopsy diagnoses are performed. This paper gives an overview over kidney biopsy registries, explores how these registries code kidney disease and identifies needs for improvement of coding practice.

Methods

A literature search was undertaken to identify biopsy registries for medical kidney diseases. These data were supplemented with information from personal contacts and from registry websites. A questionnaire was sent to all identified registries, investigating age of registries, scope, method of coding, possible mapping to international terminologies as well as self-reported problems and suggestions for improvement.

Results

Sixteen regional or national kidney biopsy registries were identified, of which 11 were older than 10 years. Most registries were located either in Europe (10/16) or in Asia (4/16). Registries most often use a proprietary coding system (12/16). Only a few of these coding systems were mapped to SNOMED CT (1), older SNOMED versions (2) or ERA-EDTA PRD (3). Lack of maintenance and updates of the coding system was the most commonly reported problem.

Conclusions

There were large gaps in the global coverage of kidney biopsy registries. Limited use of international coding systems among existing registries hampers interoperability and exchange of data. The study underlines that the use of a common and uniform coding system is necessary to fully realize the potential of kidney biopsy registries.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02365-3.

More than ancillary records: clinical implications of renal pathology examination in tumor nephrectomy specimens

Background

Nephrectomy is the management of choice for the treatment of renal tumors. Surgical pathologists primarily focus on tumor diagnosis and investigations relating to prognosis or therapy. Pathological changes in non-neoplastic tissue may, however, be relevant for further management and should be thoroughly assessed.

Methods

Here, we examined the non-neoplastic renal parenchyma in 206 tumor nephrectomy specimens for the presence of glomerular, tubulo-interstitial, or vascular lesions, and correlated them with clinical parameters and outcome of renal function.

Results

We analyzed 188 malignant and 18 benign or pseudo-tumorous lesions. The most common tumor type was clear cell renal cell carcinoma (CCRCC, n = 106) followed by papillary or urothelial carcinomas (n = 25). Renal pathology examination revealed the presence of kidney disease in 39 cases (18.9%). Glomerulonephritis was found in 15 cases (7.3%), and the most frequent was IgA nephropathy (n = 6; 2.9%). Vasculitis was found in two cases (0.9%). In 15 cases we found tubulo-interstitial nephritis, and in 9 severe diabetic or hypertensive nephropathy. Partial nephrectomy was not linked to better eGFR at follow-up. Age, vascular nephropathy, glomerular scarring and interstitial fibrosis were the leading independent negative factors influencing eGFR at time of surgery, whereas proteinuria was associated with reduced eGFR at 1 year.

Conclusion

Our large study population indicates a high incidence of renal diseases potentially relevant for the postoperative management of patients with renal neoplasia. Consistent and systematic reporting of non-neoplastic renal pathology in tumor nephrectomy specimens should therefore be mandatory.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40620-021-01030-0.

Onconephrology: The intersections between the kidney and cancer

Onconephrology is a new subspecialty of nephrology that recognizes the important intersections of kidney disease with cancer. This intersection takes many forms and includes drug-induced nephrotoxicity, electrolyte disorders, paraneoplastic glomerulonephritis, and the interactions of chronic kidney disease with cancer. Data clearly demonstrate that, when patients with cancer develop acute or chronic kidney disease, outcomes are inferior, and the promise of curative therapeutic regimens is lessened. This highlights the imperative for collaborative care between oncologists and nephrologists in recognizing and treating kidney disease in patients with cancer. In response to this need, specific training programs in onconephrology as well as dedicated onconephrology clinics have appeared. This comprehensive review covers many of the critical topics in onconephrology, with a focus on acute kidney injury, chronic kidney disease, drug-induced nephrotoxicity, kidney disease in stem cell transplantation, and electrolyte disorders in patients with cancer.

Comparison of skin cancer awareness and sun protection behaviours between renal transplant recipients and patients with glomerular disease treated with immunosuppressants

BACKGROUND

There is no previous study that compare skin cancer awareness and photoprotective behaviours between renal transplant recipients (RTR) and patients with glomerular disease (GD).

OBJECTIVES/METHODS

Sixty-one RTR and 51 patients with GD were given a self-reported questionnaire to evaluate skin cancer awareness and photoprotective behaviours in this cross-sectional study. The former group received a formal education on skin cancer and the latter an informal session prior to immunosuppressant use.

RESULTS

Ninety-three percent (n = 57) of RTRs and 88% (n = 45) of patients with GD responded to the survey. Majority of participants from both groups were aware that ultraviolet radiation could play a role in the occurrence of skin cancers and the awareness increased in participants with higher education (odds ratio [OR] = 1.50, 95% confidence interval [CI] = 1.15-1.95, P = .003). Ninety-eight percent vs 71% were aware that immunosuppressants can increase the risk of developing cancer (P < .001) and higher awareness was noted in younger participants (OR = 0.92, 95% CI = 0.87-0.97, P = .003). Suboptimal photoprotective behaviours (sun avoidance, sunscreen usage and sun-protective clothing) were noted in both cohorts and slightly lower sun protection rates were reported in RTR when compared with patients having GD. The level of sun protective measures in RTR based on high, moderate and minimal use of photoprotective measures were 21%, 46% and 33%, respectively. In terms of patients with GD, the latter practices were 13%, 50% and 37%, respectively (P = .560). Higher educational status was significantly associated with better sunscreen usage in RTR (P = .017) whereas this finding was not observed in patients with GD.

CONCLUSION

Patients with GD and RTR should have formal education on the risks of skin cancers before starting immunosuppressants. Follow-up education and surveillance is required to improve skin protective practices in these patients.

Secondary Membranous Nephropathy. A Narrative Review

Membranous nephropathy (MN) is a common cause of proteinuria and nephrotic syndrome all over the world. It can be subdivided into primary and secondary forms. Primary form is an autoimmune disease clinically characterized by nephrotic syndrome and slow progression. It accounts for ~70% cases of MN. In the remaining cases MN may be secondary to well-defined causes, including infections, drugs, cancer, or autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), urticarial vasculitis, sarcoidosis, thyroiditis, Sjogren syndrome, systemic sclerosis, or ankylosing spondylitis. The clinical presentation is similar in primary and secondary MN. However, the outcome may be different, being often related to that of the original disease in secondary MN. Also, the treatment may be different, being targeted to the etiologic cause in secondary MN. Thus, the differential diagnosis between primary and secondary MN is critical and should be based not only on history and clinical features of the patient but also on immunofluorescence and electron microscopy analysis of renal biopsy as well as on the research of circulating antibodies. The identification of the pathologic events underlying a secondary MN is of paramount importance, since the eradication of the etiologic factors may be followed by remission or definitive cure of MN. In this review we report the main diseases and drugs responsible of secondary MN, the outcome and the pathogenesis of renal disease in different settings and the possible treatments.

The link between kidney disease and cancer: complications and treatment

Acute and chronic kidney disease encompasses a complex set of diseases that can both lead to, and result from, cancer. In particular, kidney disease can arise from the use of chemotherapeutic agents. Many of the current and newly developed cancer chemotherapeutic agents are nephrotoxic and can promote kidney dysfunction, which frequently manifests during the terminal stages of cancer. Given the link between kidney disease and cancer development and treatment, the aim of this Review is to highlight the importance of multidisciplinary collaboration between oncologists and nephrologists to predict and prevent chemotherapeutic-induced nephrotoxicity. As new therapies are introduced to treat cancer, new renal toxicities require proper diagnosis and management. We anticipate that multidisciplinary collaborations will lead to the development and implementation of guidelines for clinicians to improve the therapeutic management of patients with both cancer and renal impairment.

Cancer development and mortality differences in patients with glomerulonephritis after renal biopsy: a single center retrospective cohort study

Background

The association between glomerulonephritis (GN) and cancer has been well known for decades. However, studies evaluating long-term de novo cancer development in patients with GN are limited. This study aimed to evaluate the incidence of cancer development among patients with renal biopsy-proven GN during post-biopsy follow-up and the differences in outcomes according to cancer occurrence.

Methods

We conducted a retrospective cohort study of adult patients who underwent renal biopsy at Seoul National Bundang Hospital between 2003 and 2017. After excluding 778 patients with age < 18 years, cancer diagnosis before or within 6 months after renal biopsy, immunosuppressant therapy before renal biopsy, or pathologic diagnoses other than GN, 822 patients were included in the analysis. Data on baseline clinical characteristics, renal biopsy results, and types and doses of immunosuppressant agents were collected from electronic medical records. The incidence of cancer was censored on the date when the first cancer was diagnosed. We evaluated rates of mortality and end-stage renal disease (ESRD) development during follow-up.

Results

During a mean follow-up period of 58.9 ± 44.5 months, 45 subjects (5.5%) developed de novo cancer. A comparison of clinical characteristics between subjects who did and did not develop cancer revealed that cancer patients were older and had higher comorbidities and immunosuppressant use. Overall, patients with GN had an elevated standardized incidence ratio (SIR) of 7.16 (95% confidence interval (CI): 5.22–9.61) relative to the age- and sex-matched general population. In particular, the SIR was significantly higher in GNs such as membranous nephropathy (MN), IgA nephropathy, lupus nephritis, and focal segmental glomerulosclerosis. Multivariable Cox proportional hazard model revealed that patients with MN had an increased risk of cancer development, with a hazard ratio of 2.30 [95% CI: 1.06–4.98]. Patients with MN who developed cancer had a significantly higher risk of mortality (hazard ratio: 6.59; 95% CI: 1.22–35.56, P = 0.03) than those without cancer, but there was a non-significant difference in ESRD development. Conclusions: Patients with GN without concurrent cancer, particularly those with MN, have significantly higher risks of cancer development and subsequent mortality and should remain aware of the potential development of malignancy during follow-up.

Identifying Outcomes Important to Patients with Glomerular Disease and Their Caregivers

BACKGROUND AND OBJECTIVES

Shared decision making in patients with glomerular disease remains challenging because outcomes important to patients remain largely unknown. We aimed to identify and prioritize outcomes important to patients and caregivers and to describe reasons for their choices.

DESIGN

, setting, participants, & measurementsWe purposively sampled adult patients with glomerular disease and their caregivers from Australia, Hong Kong, the United Kingdom, and the United States. Participants identified, discussed, and ranked outcomes in focus groups using the nominal group technique; a relative importance score (between zero and one) was calculated. Qualitative data were analyzed thematically.

RESULTS

Across 16 focus groups, 134 participants (range, 19-85 years old; 51% women), including 101 patients and 33 caregivers, identified 58 outcomes. The ten highest-ranked outcomes were kidney function (importance score of 0.42), mortality (0.29), need for dialysis or transplant (0.22), life participation (0.18), fatigue (0.17), anxiety (0.13), family impact (0.12), infection and immunity (0.12), ability to work (0.11), and BP (0.11). Three themes explained the reasons for these rankings: constraining day-to-day experience, impaired agency and control over health, and threats to future health and family.

CONCLUSIONS

Patients with glomerular disease and their caregivers highly prioritize kidney health and survival, but they also prioritize life participation, fatigue, anxiety, and family impact.

Comparison of cancer prevalence between patients with glomerulonephritis and the general population at the time of kidney biopsy

Glomerulonephritis (GN) has been associated with many solid and hematologic malignancies. However, cancer prevalence at the time of GN diagnosis has been rarely examined. We aimed to evaluate the cancer prevalence in patients with GN at the time of kidney biopsy and to compare the results to those of the general population. A total of 1,155 patients who underwent kidney biopsy between 2003 and 2017 were included. We investigated patients diagnosed with cancer within one month of kidney biopsy. The occurrence of cancer was compared with that of the Korean general population using the observed-to-expected rates (O/E ratio). Twenty-nine patients with GN had cancer. The mean age of patients with and without cancer was 49 and 66 years old, respectively. The proportion of male patients with and without cancer was 49.4% and 58.6%, respectively. The glomerular filtration rate was different between the groups (78.1 ± 37.0, 58.0 ± 43.6 ml/min/1.73 m2, p = 0.006), but the urine protein/creatinine ratio was not (3.21 ± 4.01, 5.38 ± 7.47 g/gCr, p = 0.172). Immunoglobulin A nephropathy (IgAN) was the most common GN (37.9%), followed by membranous GN (13.5%), focal segmental glomerulosclerosis (9.7%), minimal change disease (9.2%), amyloidosis (1.2%). Amyloidosis was the most common GN associated with malignancy (20.7%). In patients with amyloidosis, cancer was observed almost 28 times more than expected and these patients showed higher cancer occurrence than patients with other GN (Relative Risk [RR]: 15.73; 95% confidence interval [CI]: 4.82-51.30; p < 0.01). Cancer occurrence was three times greater in GN patients aged > 50 years compared to the general population (O/E ratio: 3.42; 95% CI: 1.37-5.46; p = 0.027). Patients with GN, especially amyloidosis, have higher risk of cancer than the general population at the time of GN diagnosis. Older age (> 50 years) was one of the major determinants of the presence of cancer in GN patients.

Hypertensive nephropathy is associated with an increased risk of myeloma, skin, and renal cancer

Previous studies suggest an increased cancer risk in hypertension. Patients with hypertensive nephropathy have not been studied. A national registry study was performed to assess the presence and size of this association. Clinical data and cancer diagnoses for all patients with biopsy-proven hypertensive nephropathy between 1985 and 2015 in Denmark were extracted from four national registries and compared with age- and sex-adjusted national cancer rates. The risk of cancer was twice the background population. It was raised for renal cancer (odds ratio 10.4), myeloma (13.2), skin cancer (7.9), and other/unspecified (1.8). No increase in incidence was seen until 1 year before renal biopsy and then rose rapidly. It was again normal 5 years after biopsy. Hypertensive nephropathy is associated with an increased risk of myeloma, skin, renal, and other cancers. Screening of patients with hypertensive nephropathy, in the presence of reduced renal function or significant proteinuria, may be indicated.

ANCA-Associated Vasculitides and Hematologic Malignancies: Lessons from the Past and Future Perspectives

The purpose of this paper is to collect and summarize all evidences relating to an association between ANCA-associated vasculitides (AAVs) and hematologic malignancies, in the form of either a paraneoplastic vasculitis or leukemias and lymphomas developing on a preexisting vasculitis. Additionally, the role of cyclophosphamide in vasculitis treatment has been assessed and compared to rituximab. Paraneoplastic AAV seems to be an uncommon presentation of hemopathies. Hematologic malignancy risk in AAV is more likely to be increased by cyclophosphamide, although not yet definitely proven. Furthermore, the pathogenesis of ANCA-associated vasculitis has been reviewed with particular emphasis on the role of proteinase 3 (PR3) in fuelling granulomatosis with polyangiitis (GPA) inflammation. PR3 is a bactericidal protein expressed by neutrophilic granules and on their plasma membrane. Derangements in its expression and function have been linked to leukemias and GPA alike. PR3-derived PR1 peptide is being studied as an immunotherapy target in leukemia and multiple myeloma. This study is aimed at bringing together various evidences from the field of immunological and hematological research, at exposing contradictions, and at revealing novel insights on the association between ANCA-associated vasculitis and hematologic malignancies.

Antigen-Specific IgG Subclasses in Primary and Malignancy-Associated Membranous Nephropathy

Membranous nephropathy (MN) is an autoimmune disease caused by binding of circulating antibodies to podocyte antigens in the kidney. For decades and still today primary MN has been considered to have an unspecified IgG4-driven autoimmune genesis, while secondary MN has been associated with other diseases, most notably cancer, and not linked to IgG4. Immunologic mechanisms of primary and malignancy-associated MN are assumed to be different, however, this has never been systematically evaluated. The identification of Phospholipase A₂ Receptor 1 (PLA₂R1) and Thrombospondin Type-1 Domain-Containing 7A (THSD7A) as target antigens in MN allows a pathogenesis-driven differential diagnosis. Recent data showing a molecular link between increased THSD7A-expression in tumors and THSD7A-antibody positive MN suggest a similar pathogenesis of malignancy-associated and primary MN. In order to better define the underlying immunologic processes, we systematically analyzed circulating antigen-specific IgG subclasses in the serum of 76 patients with PLA₂R1-associated MN and 41 patients with THSD7A-associated MN in relationship to concurrent malignancy and disease outcome. Twenty-three patients in the study had malignancy-associated MN. We analyzed antigen-specific IgG subclasses in the serum of all patients at baseline and in 55 patients during follow-up by Western blot applying antigens derived from human kidney and lung. At baseline all 117 patients were positive for IgG4-antibodies against either PLA₂R1 or THSD7A, while IgG3, IgG1, and IgG2-antibodies were found in 87, 72, and 26% of patients, respectively. There were no differences in the IgG subclass distribution between patients with primary vs. cancer-associated MN and no association with disease outcome. Moreover, levels of antigen-specific IgG4-antibodies were not different between primary and malignancy-associated MN and levels of all IgG subclasses did not differ between these groups. Both podocytes and lung bronchioles showed expression of both PLA₂R1 and THSD7A when analyzed by immunofluorescence and Western blot. Every antigen-specific IgG subclass showed identical binding in both organs and autoantibodies bound the respective antigen only under non-reducing conditions. We conclude that antigen-specific IgG subclasses do not differentiate primary from malignancy-associated MN or predict disease prognosis. These data support the view that one common pathway may lead to primary and cancer-associated MN induced by PLA₂R1- or THSD7A-antibodies.